GB841132A - - Google Patents

Abstract

841,132. Grid resistors: electric couplings. SATCHWELL, L. May 23,1956 [May 24, 1955], No. 14951/55. Classes 37 and 38(1). A resistance comprises one or more plates cut to zig-zag form and folded transversely to U- shape about midway of the length, the ends being clamped between insulating supports so as to form a rigid triangular structure, free to expand on heating. Fig. 6 shows a parallelogram of sheet metal having staggered slots to provide a zig-zag current path bent into a U-shaped channel, Fig. 8 with flanged edges 12a and offset ends on opposite sides to facilitate making end connections. Fig. 4 shows a plurality of such elements arranged symmetrically about an insulating support comprising a number of insulating blocks 10b having on opposite faces complementary channels and projections as at 10c, 10d between which the flanged edges 12a are gripped ; distance pieces 16 (Fig. 3) being inserted in place of the offset ends of each element. The complete assembly is clamped between two plates 20, 21 by threaded rods 11, which may be covered with an insulant, passing through a hole in each block. The interstices between the blocks may be filled with a heat resistant insulating cement. Couplings. Adjacent elements on opposite sides of the support are connected in series by U- shaped plates 24, Figs. 3, 5, attached by spot welding. The groups of elements so formed are connected in series by plates 23, Fig. 4, bent into U-shape. A pair of terminals 25 are attached to the assembly by welding between the L-shaped plates 22 (attached to the end elements) and the distance pieces 16.